Extendable boom



L. J. LANDRY EXTENDABLE BOOM July 13, 1965 '3 Sheets-Sheet 1 Filed me,1962 Louis J Landry INVENTOR- L. J. LANDRY EXTENDABLE BOOM July 13',1965 s Sheets-Sheet 2 Filed 001'.- 8. 1962 m& m& N9

wk vm 3 N Eh Louis J Landry INVENTOR.

July 1 3, 1965 J. LANDRY I EXTENDABLE BOOM Filed Oct. 8.1962

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3 Sheets-Sheet 3 Louis J Landry mmvrm United States Patent 3,194,413EXTENDABLE BOOM Louis J. Landry, 210 Darbonne St., Sulphur, La. FiledOct. 8, 1962, Ser. No. 229,081 7 Claims. (Cl. 212-55) This inventionrelates to a novel and useful extendable crane boom and morespecifically to a crane boom including inner and outer sections mountedtogether for longitudinal extension and retraction. In addition, thecrane boom of the instant invention is designed specifically as areplacement for a rigid boom on substantially any type of cranepresently in use. The extendable boom of the instant invention includespennant lines which are reeved in a manner enabling the extendable boomto be used on any type of crane having a gantry assembly. Still further,the extendable boom of the instant invention is provided with Winchbeams for raising and lowering the free end of the boom and forextending and retracting the extendable sections of the boom. In thismanner, any suitable source of power may be utilized.

In addition to the above, the extendable boom of the instant inventionhas its inner and outer extendable sections constructed in a mannerwhereby the inner upper section is guidingly mounted for longitudinalreciprocal movement and against lateral movement relative to the outerlower section in at least three different directions. Still further, theextendable boom also includes means for guidingly supporting the upperinner section thereof against rotational movement about its longitudinalaxis relative to the outer lower boom section.

The main object of this invention is to provide an extendable boom whichmay be readily utilized as a replacement for the rigid boom onsubstantially any type of crane utilizing a gantry assembly.

A further object of this invention is to provide an extendable boom inaccordance with the immediately pre ceding object having electric motormeans drivingly connected to winch means mounted thereon for raising andlowering the free end of the boom and for extending and retracting'theupper inner section of the boom.

Another object of this invention is to provide an extendable boom withthe telescoped sections thereof constructed in a manner whereby theupper inner section of the boom is guidingly supported from the lowersection thereof for longitudinal reciprocal movement and against lateralmovement in at least three directions relative to the outer lowersection of the boom.

Yet another object of this invention, in accordance with the immediatelypreceding object, is to provide an extendable boom whose upper innersection is supported from the outer lower section for longitudinalextension and retraction and against rotational movement relative to thelower outer boom section.

A final object of this invention to be specifically enumerated herein isto provide an extendable boom in accordance with the preceding objectswhich will conform to conventional forms of manufacture, be of simpleconstruction and easy to operate so as to provide a device which will beeconomically feasible, long-lasting and relatively trouble-free inoperation.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming a part hereof, whereinlike numerals refer to like parts throughout, and in which:

FIGURE 1 is a side elevational view of a crane having the extendableboom of the instant invention mounted thereon;

FIGURE 2 is a fragmentary top plan View of the em- 3,l4,4l3 Patented.luly 13, I965 bodiment illustrated in FIGURE 1 on somewhat of anenlarged scale;

FIGURE 3 is a fragmentary enlarged sectional view taken substantiallyupon the plane indicated by section line 3-3 of FIGURE 2;

FIGURE 4 is an enlarged transverse sectional view taken substantiallyupon the plane indicated by section line 4-4 of FIGURE 3, with only asingle lift line pulley shown;

FIGURE 5 is a transverse sectional view taken substantially upon theplane indicated by section line 5-5 of FIGURE 2 and on somewhat of anenlarged scale;

FIGURE 6 is an enlarged fragmentary sectional view taken substantiallyupon the plane indicated by section line t6 of FIGURE 3;

FIGURE 7 is a fragmentary perspective view of the supporting cables forthe extendable boom showing the manner in which the pennant lines may bereeved over the gantry assembly of a crane and the manner in which thewinch means carried by the extendable boom may be utilized to raise andlower the free end of the boom and also to extend and retract theextendable upper inner section of the boom; and

FIGURE 8 is a fragmentary enlarged perspective view of the upper end ofthe extendable upper inner section of the boom shown with the head endthereof removed.

Referring now more specifically to the drawings, the numeral 10generally designates a conventional type of crane. The crane It)includes a platform or base generally referred to by the referencenumeral 12 which is supported by means of a crawler tread assemblygenerally referred to by the reference numeral 14. A cab and prime moverhousing generally referred to by the reference numeral 16 is supportedfrom the main frame of base 12 and it may be seen that a gantry assemblygenerally referred to by the reference numeral 18 is supported from theupper portion of the cab and prime mover housing 16.

The mounting frame or base 12 includes a pair of mounting flanges 20 towhich the lower end of the extendable boom 22 is pivotally secured bymeans of an axle pin 24. The extendable boom 22 includes a pyramidalbutt section generally referred to by the reference numeral 26, a mainsection generally referred to by the reference number 28 and a generallypyramidal head section generally referred to by the reference numeral30.

With attention now directed more specifically to FIG- URES 2, 3, 8 ofthe drawings it may be seen that the butt section 26 includes anelectric motor 32 which is drivingly connected to a gear reductionassembly 34 having an output shaft 36. The output shaft 36 is drivinglyconnected to a main winding drum assembly 38 including first and secondhalves 40 and 42 separated by a divider flange 44. In addition, a pairof auxiliary winding drums 46 and 43 are supported from the butt section26 and are rotated from the main winding drum 38 through a pair ofclutch and brake assemblies 50 and 52 respectively. The clutch and brakeassemblies 50 and 52 may be of conventional design similar to those nowin use on existing cranes. It will be noted that the main winding drum38 is approximately twice as great in circumference as the auxiliarywinding drums 46 and 48.

The main section 28 of the boom 22 comprises an upper inner sectiongenerally referred to by the reference numeral 54 and an outer lowersection generally referred to by the reference numeral 56. The outerlower section 56 includes four generally parallel and longitudinallyextending angle members 58 which form the four corner longitudinal edges69 of the outer lower section 56. Corresponding ends of the four anglemembers 58 are interconnected by means of four transversely extend bracemembers 62. In addit each P of adlacent together for relative movementbetween extended and retracted positions, a gantry assembly supportedfrom said frame and elevated above the lower end of said lower section,a first cable supporting said boom and having one end operativelyconnected to reversible winding means carried by said lower section andthe other end connected to said upper section, means reeving said firstcable between said winding means, said gantry, and the upper end of saidupper section, a second lift cable having one end operatively connectedto said winding means and the other end connected to the lower end ofsaid upper section, means reeving said second cable between said windingmeans, the upper end of said lower section, and the lower end of saidupper section, said winding means including means for inversely windingand unwinding said first and second cables at rates enabling the angleof said boom to be maintained substantially constant during extensionand retraction of said boom, said reversible winding means being spacedtoward the upper end of said boom from its axis of rotation relative tosaid frame, and said gantry being spaced above said axis a distancegreater than the distance between said axis and said winding means.

2. The combination of claim 1 wherein said winding means includes meansfor also winding and unwinding one of said cables independently of theother of said cables.

3. The combination of claim 1 wherein said outer section includesdiagonal braces forming each of the sides thereof secured between theouter surfaces of the adjacent flanges of adjacent angle members.

4. The combination of claim 1 wherein said inner section includesdiagonal braces forming each of the sides thereof secured between theinner surfaces of the adjacent flanges of adjacent angle members.

5. In combination, a mounting frame, an upstanding boom pivotallysecured at its lower end to said frame for movement about a horizontalaxis, said boom including upper inner and lower outer sections mountedtogether for relative movement between extended and retracted positions,a gantry assembly supported from said frame and elevated above the lowerend of said lower section, a first cable supporting said boom and havingone end operatively connected to reversible winding means carried bysaid lower section and the other end connected to said upper section,means reeving said first cable between said winding means, said gantry,and the upper end of said upper section, a second lift cable having oneend operatively connected to said winding means and the other endconnected to the lower end of said upper section, means reeving saidsecond cable between said winding means, the upper end of said lowersection, and the lower end of said upper section, said winding meansincluding means for inversely winding and unwinding said first andsecond cables at rates enabling the angle of said boom to be maintainedgenerally constant during extension and retraction of said boom, saidreversible winding means being spaced toward the upper end of said boomfrom its axis of rotation relative to said frame, and said gantry beingspaced above said axis a distance greater than the distance between saidaxis and said winding means, said inner and outer end sections eachbeing generally polygonal in cross section and including a plurality oflongitudinally extending and generally parallel angle members openingdiagonally inwardly extending along each corner edge thereof, each ofsaid angle members including a pair of angularly disposed longitudinallyextending flanges generally paralleling the adjacent sides of thecorresponding boom section, each of said angle members including aplurality of flanged rollers spaced longitudinally thereof eachjournalled for rotation about an axis extending transversely thereof anddisposed in a plane generally paralleling the plane in which one of theflanges thereof is disposed, each of said rollers being disposed on theside of said one flange adjacent the corresponding flange of the othersection and disposed in rolling contact with the side of saidcorresponding flange and with the inner side of its flange engaging thefree longitudinal edge of said corresponding flange.

6. The combination of claim 5, said winding means including means foralso winding and unwinding one of said cables independently of the otherof said cables.

7. .In combination, a mounting frame, an upstanding boom pivotallysecured at its lower end to said frame for movement about a horizontalaxis, said boom including upper inner and lower outer sections mountedtogether for relative movement between extended and protractedpositions, means connected between said boom and said frame for pivotingsaid boom about said axis and for extending said upper section relativeto said lower section, said inner and outer sections each beinggenerally polygonal in cross section and including a plurality oflongitudinally extending and generally parallel angled members openingdiagonally inwardly extending along each corner edge thereof, each ofsaid angle members including a pair of angularly disposed longitudinallyextending flanges generally paralleling the adjacent sides of thecorresponding boom section, each of said angle members including aplurality of flanged rollers spaced longitudi nally thereof eachjournalled for rotation about an axis extending tranversely thereof anddisposed in a plane generally paralleling the plane in which one of theflanges thereof is disposed, each of said rollers being disposed on theside of said one flange adjacent the corresponding flange of the othersection and disposed in rolling contact with the side of saidcorresponding flange and with the inner side of its flange engaging thefree longitudinal edge of said corresponding flange.

References Cited by the Examiner UNITED STATES PATENTS 2,545,047 3 51Russell 2 12--5 5 2,819,803 1/58 Obenchain 2l255 3,029,954 4/62 Grant212--55 3,073,457 1/63 Thomas 242-144 SAMUEL F. COLEMAN, PrimaryExaminer.

KARL J, ALBRECHT, ERNEST A. FALLER,

Examiners.

1. IN COMBINATION, A MOUNTING FRAME, AN UPSTANDING BOOM PIVOTALLYSECURED AT ITS LOWER END TO SAID FRAME FOR MOVEMENT ABOUT A HORIZONTALAXIS, SAID BOOM INCLUDING UPPER INNER AND LOWER OUTER SECTIONS MOUNTEDTOGETHER FOR RELATIVE MOVEMENT BETWEEN EXTENDED AND RETRACTED POSITIONS,A GANTRY ASSEMBLY SUPPORTED FROM SAID FRAME AND ELEVATED ABOVE THE LOWEREND OF SAID LOWER SECTION, A FIRST CABLE SUPPORTING SAID BOOM AND HAVINGONE END OPERATIVELY CONNECTED TO REVERSIBLE WINDING MEANS CARRIED BYSAID LOWER SECTION AND THE OTHER END CONNECTED TO SAID UPPER SECTION,MEANS REEVING SAID FIRST CABLE BETWEEN SAID WINDING MEANS, SAID GANTRY,AND THE UPPER END OF SAID UPPER SECTION, A SECOND LIFT CABLE HAVING ONEEND OPERATIVELY CONNECTED TO SAID WINDING MEANS AND THE OTHER ENDCONNECTED TO THE LOWER END OF SAID UPPER SECTION, MEANS REEVING SAIDSECOND CABLE BE-